Some set-top boxes and other electronic devices use a multi-processor computer chip, such as a Secure Media Processor chip, which uses a multiprocessor computer architecture. In secure multiprocessor computer chip architectures, a security processor and a main processor are typically connected to a single main memory. As the name suggests, the security processor is more secure and less vulnerable to attack by a hacker than the main processor.
The security processor functions to control a boot-up process of the main processor as well as access to encrypted content by the main processor. During a boot-up process, the security processor boots up first to authenticate the main processor's code and then the authenticated code is loaded into the main processor to run. In addition, for the main processor to access encrypted content, the security processor issues keys for a decryption engine to decrypt the content to be accessible to the main processor. As such, if the security processor stops issuing the keys, access to the encrypted content by the main processor is ceased.
In various instances, a hacker may be able to activate a debugging function on the main processor during the boot-up operation. Oftentimes, due to chip design architecture, for instance, the debug function of the main processor may not be disabled. This unauthorized access may allow a hacker to modify code of the main processor to gain access to private information or other protected content.